Alarm system and clock therefor



June 21, 1966 R H. ROGERS ETAL ALARM SYSTEM AND CLOCK THEREFOR 5Sheets-Sheet l Filed Deo. 30, 1963 June 21, 1966 R H. ROGRS ETAL ALARMSYSTEM AND @Loox THEREFGR (5 Sheets-Sheet 2 vFiled Dec. 30, 1965INVENTORS JOHN A. SADLER RICHARD H. ROGERS Bw y, i, ATTORNEYS June 21,1966 R. H. RCGERS ETAL. 3,257,554

ALARM SYSTEM AND CLOCK THEREFOR Filed Deo. 30, 1963 5 Sheets-Sheet 5FlG. 3

FIG. 4

FlG. 5

INVENTORS JOHN A SADLER RICHARD H. ROGERS ATTORNEYS 4 is cold and itsresistance is low.

United States Patent O 3,257,654 ALARM SYSTEM AND vCLOCK THEREFGRRichard H. Rogers, Toronto, Ontario, and .lohn A. Sadler,

Rexdale, Ontario, Canada, assignors, by mesne assignments, toChubb-Mosler and Taylor Safes Ltd., Brampton, Untario, Canada Filed Dec.30, 1963, Ser. No. 334,296 25 Claims. (Cl. 340-276) This inventionrelates to an alarm system clock and to an alarm system incorporatingthe clock.

IIt is an object of the invention to provide reliable and simple timingmeans for an alarm system. The invention provides a clock for puttingthe system into its on Iguard condition at desired times, and for timingthe duration of -an alarm condition.

The invention is illustrated by way of example in the accompanyingdrawings in which:

FIG. 1 is an electrical circuit diagram of apparatus that is located ina vault;

FIG. 2 is an electrical circuit diagram of' a bell or alarm unit that islocated outside `the vault but is electrically connected to the unit `ofFIG. 1;

IFIG. 3 is a plan view of a clock for the vault unit;

FIG. 4 is a partly sectional side View of the clock; and

IFIG. 5 is an enlarged sectional View taken along the vertical planeindicated by the line 5 5 in FIG. 3.

The alarm Iunit of FIG. 2 can be mounted on an outside Wall of a bank,preferably at a relatively inaccessible location. All parts of the unitare housed in a sealed box, from which a line runs to the vault unit ofFIG. 1, the line consisting of la pair of -wires and 11. The wires 10and I11 normally carry an oscillatory signal trom the vault unit. Aswill presently be explained, when this signal is present a bell 13 (orother annunciator) in the alarm unit is prevented from ringing.

The wiresrltl and 11 also conduct'DC. charging current vto a six-voltbattery V14 in the alarm unit. The DE.' flows to the battery through achoke d5, which impedes the oscillatory signal, and through a lamp 16.4The lamp 16 is notemployed to give a visual indication; rather it is aconvenient electrical resistive means. Under normal con ditions `thereis a D.C. voltage across the wires 10 and 11 substantially equal to thevoltage of battery 14, so that only a small current ows through the lamp16, the lamp l-f, however, a short should occur across the wires 10 andl11, the lamp would have substantially full battery voltage connectedacross it, causing the lamp to heat rapidly. The lamp has a hi-ghtemperature coetlcient of resistance, and therefore its resistancequickly rises to place only a small load on the battery and prevent itsrapid discharge. Consequently if a burglar should attempt to defeat thesystem by shorting the wires 10 and y11 he would not succeed in quicklydischarging the battery to deprive the system of a power source forringing the bell 13. 'If a high voltage were placed across the wires 10and 11 with the object of destroying the battery, the lamp 16 would burnout and thereby protect the battery.

The oscillatory signal normally supplied over the wires 10 and 11 passesthrough a capacitor 17 to `a resonant reed receiver 18. The signalcauses reed contacts .19 to make and break alternately, thus supplying apulsating D.C. output signal which is 'filtered by a capacitor 20 andresistor 2.1 and applied across an emitter-base resistor 22 of atransistor amplier A23. This signal holds the transistor 23 on. Aturther transistor 24, biased by a resistor 25 and diode 26, is held offby the. potential drop across resistor 27 when the transistor 23 is on.If the oscillatory signal supplied over the wires 10 and 11 disappears,the reed contacts 19 remain open, the transistor 23 goes off, thetransistorvalve 124 turns on, and current flows through ice a relay coil28 to close relay contacts 29 and energize the bell 13 rfrom the battery111i.

lNow referring to the vault unit shown in FIG. 1 a power supply 30is'supplied from `an A.C. line 31. The power supply 30 includes arectier and lter (not shown) for supplying six-volts DC. across thewires lil and 11 which run to the alarm unit of FIG. 2. A capacitor 32is the nal smoothing capacitor of the iilter. The power supply 30furnishes charging current for the battery .14 of the alarm funit andalso supplies power for the vault unit, the sole battery in the systembeing the one in the `alarm Iunit. This battery 14 supplies power forthe whole system if the A.C. supply on line 3.1 should tail. Becausecharging current is supplied to the battery 14 over the wires 10 and 11,the battery can be relatively small and yet have a long life.

The oscillatory signal for the wires 10 and 11 is supplied by a tuningfork oscillator 33. Power lfor the oscillatoris supplied by the powersupply 3i) through a choke 34 (which keeps the oscilla-tory signal outof the power supply) and through a coil 35 and diode 36. The oscillatoris self starting, and thus generates an oscillatory signal as soon as itreceives power. The signal from the oscillator passes through acapacitor 137 to the wire |10. It also passes through a capacitor 33, isrectiiied by diodes 39, 40 and ltered by a capacitor -41 and resistor`4-2, and applied across an emitter-base resistor 43 of a transistoramplifier `411i. The signal holds the transistor 44 on. A furthertransistor 45, biased by a resistor 46 and diode 47, is heldinopera-tive by the potential drop across resistor Sii when thetransistor 44 is on. If the signal `from the oscillator .shouldmomentarily fail (causing the bell 13 to ring), transistor 44. wouldturn ofi, causing transistor valve 45 to turn on. This shunts theoscillator 33 so that its signal remains off The D.C. current throughthe coil 35 is increased. As will be more fully explained, the coil 35is part of a timer of the clock of this invention, 4and when actuated bythe increased D.C. current the timer requires a predetermined time toelapse (for example, tifteen minutes, during which the bell 13 continuesto ring) and then momentarily closes a switch 49. This suppliessuilicient voltage to the -oscillator 33 to resume its operation, sothat the oscillatory signal can reappear .to turn off the bell 13 andthe transistor 45 and thus remove the D C. which actua-tes the timercoil 35. The oscillatory signal thus normally holds the coil 35inoperative. A choke 50 prevents the oscillatory signal from beingshunted through the oscillator when the switch 49 is closed.

If the line lll, 11 is momentarily opened, the oscillatory signal to thealarm unit is lost and the bell rings. The power supply 30 loses part ofits load, and it is deliberately given .poor voltage regulation so thatits D.C. output voltage rises. This rise in voltage causes a Zener diode51 to conduct, causing a voltage drop across a resistor 52 and therebybiasing the oscillator oit. This causes the transistor valve 45 to beturned on, shunting the oscillator, so that the aforementionedpredetermined time must again elapse before the oscillator can come onagain. The amount of hum in the power supply 30 also changes if the line10, 11 is open circuited, and this change in the operation of the powersupply could, instead of its rise in voltage, be sensed to render theoscillator inoperative.

The Vault unit has -several switches 53a, 53h, 53C, and 53d which areganged together and which are moved to the position shown in FIG. 1 attimes when the system is to be on guard against intruders. In serieswith the switch 53a is a door switch 54 which closes if an intruderenters. This shunts the power supply 3@ and the oscillatory signal, andthe bell in the alarm unit rings as long as the switch 54 remainsclosed. When the switch 54is Patented June 21, 1966 reopened, the timedelay required to charge the capacitor 41 prevents the transistor valve44 from turning on before the transistor valve 45, so that inA responseto the resumption of power the latter transistor 45 turns on, actuatesthe timer coil 35, and holds the oscillator off until the timer closesthe switch 49.

Another switch 53b connects a microphone 55 to the input of an audioamplifier 56. The amplier is supplied with DC. from the supply 30through a choke 57 which blocks the oscillator output signal. A Zenerdiode 58, resistor 59 and capacitor 60 maintain a constant DC. Voltagesupply to the amplifier so that the gain of the amplifier does not vary.The output of the amplifier passes through a capacitor 61 and isrectified by diodes 62 and 63 to turn off the transistor 44 in responseto a noise picked up by the microphone 55. This turns on the transistor45, which actuates the timer coil 35 and turns off the oscillator 33until the predetermined time has elapsed. If desired the audio amplifiercan include a short term memory circuit which requires a microphonenoise signal that exceeds a given level or duration before turning offthe transistor 4d.

it will be apparent that the usual teller buttons, indicator lights andthe like can be connected into the system by the switches 53e and 53d. Aline can also be run to an alarm in the police station to alert thepolice when the system is disturbed. Anti-tamper switches can beprovided in parallel withthe switch 54 to close if unauthorized personsseek access to the vault or alarm units.

FIGS. 3, 4 and 5 show a clock for operating the Vswitches 53a, 53h, 53Cand 53d. The clock has, within a casing 69 a conventional mechanicallywound spring driven mechanism that will operate for at least fourteendays without rewinding. by means of a shaft 70. A rotatable spindle 71of the clock mechanism protrudes upwardly from the casing around theshaft 70. Around the spindle is a sleeve 72 keyed at '72a with thespindle to rotate therewith. Between a shoulder 73 near the lower end ofthe sleeve and a metal washer 74 near its upper end is a stack of metaldiscs numbered from 75 to S1. The washer 74 is held against the stack ofdiscs by a clip 32 sprung into a groove of the sleeve. The discs '77 and79 are not keyed to the sleeve, but the sleeve has a fiat 72b to whichthe discs, other than 77 and 79, conform so that they must rotate withthe sleeve. A'nut 83, threaded onto the end of the spindle, is normallytightened down against the washer 74 to compress the stack and force thediscs 77 and 79 to rotate with the sleeve and spindle. Thus the stack ofdiscs forms part of the constantly driven mechanism of the clock. Thismechanism rotates once every twentyfour hours in the direction of thearrow 84 in FIG. 3, and the top disc 81 has a dial 81a to show the timeof day opposite a stationary pointer represented in FIG. 3 by an arrow85, the time indicated in FIG. 3 being 9:00 a.m. If this time indicatedshould happen to be incorrect, knobs 86 on the disc 81 can be used torotate the clock mechanism manually and set .the correct time oppositethe pointer S5. The disc 79'has an arm labelled D and the disc 77 has anarm labelled N. In FlG. 3 the arm labelled N (for night) is set at 6:00pm. and the arm labelled D (for day) at 6:00 am. For these settings theswitches 53a to 55d are to be moved to the on guard position of FIG. 1at 6:00 p.m. and are to be moved to their other, or olf guard position,at 6:00 am. Thus, as the clock mechanism rotates from the time of dayindicated in FIG. 3 (9:00 am.) to 6:00 pm. and the arm N comes oppositethe pointer S and at the underside of the arm N a lug 87 `cornes intocontact with a switch arm 88, forcing the arm 88 to pivot to the rightabout its Vaxle 88a and moving the ganged switches 53a to 53d to the onguard position. At 6:00 am. the following morning (which will beThursday morning for the arrangement shown) the arm D comes opposite thepointer 85. The arm D is sufficiently long to Contact a Vertical pin S9,

The mechanism can be wound designated THUR. (for Thursday), mounted onan adjacent rotatable day wheel 90. The arm D by engaging the pin THUR.rotates the wheel 90 until the pin THUR. reaches approximately theposition formerly occupied by the pin WED., i.e., a position opposite astationary pointer 91, when the arm D is no longer long enough tocontinue engaging the pin THUR. and the wheel 90 ceases its movement. Asthe pin THUR. is moved by the arm D past the switch arm 8S (at 6:00a.m.)l it encounters the arm 8S and moves it to the left (ie. to theposition illustrated in FIG. 3), switching the system to the o guardcondition. The pin SUN. is shown pulled up relatively to the t other daypins on the wheel 90 so that when it is the V6:00 am. Sunday), itwouldbe encounter the arm turn of the SUN. pin to be moved by the arm D pastthe switch arm 8S the SUN. pin fails to strike the `arm S8 and thesystem remains on guard, Sunday being a holiday. If however authorizedpersons planned to work in the bank on Sunday, the SUN. pin would bepushed down to a position like that shown for the other pins, and in itsdown position, as the SUN. pin was moved past the switch arm 8S (underthe influence of the arm D at 33 and push it to the left, switching thesystem to the off guard condition. Thus, whether on a given day thesystem is to be oi guard from 6:00 a.m. to 6:00 pm. depends on whetherthe pin for that day is pushed down. The arm N ensures that the systemis on guard every night from 6:00 pm. to 6:00 am. The hours for whichthe arms D and N are set can be changed by loosening the nut S3 androtating the arms to new positions relative tothe dial markings Sie.

To ensure that the wheel is properly positioned after the arm Ddisengages a pin, there is provided at the underside of the wheel 90 adetent 92 which is spring pressed upwardly to center in one of sevenconical recesses 93 located radially inwardly from the pins. The

Vdetent 92, when centered in a recess 93, positions the wheel 90correctly for the next engagement of the arm D with a day pin; when thearm D disengages a pin, it has pushed the wheel 90 slightly beyond thiscorrect position so that next time around the arm D might jam or bind`on the next pin, but the detent 92 by seating in a conical rece-ss 93pulls the wheel back to the correct position for the next engagement.Thus each day the wheel 90 is turned one seventh of a revolution by theclock mechanism. The pins are not easily removed from the day wheel, andspring pressed detents 94 which seat in necks 89a of the pins facilitatepositive location of the pins in their pushed downV or pulled upposition-s.

VBelow the lowermost disc 75 of the clock mechanism, and resting on afiber washer 95, is a cup 96 having an inner hub 96a journalled on thespindle 71 and sleeve 72. Fixed within the cup, and coaxial with thedisc 75, is the timer coil 35 which is connected into the circuit ofFIG. l by iexible leads 97 (FIG. 3). When the coil 35 is in its normalcondition, i.e., not energized by current owing through the transistor45, the cup 96 rests on the washer 95, and an arm 96b xed to the cup isheld by a spring 98 against a stop 99 so that the cup is held stationaryas the clock mechanism rotates. The cup 96 and the discs 75 and 76 areof magnetizable material, whereas the washer is of non-magnetizablematerial. When the timer coil 35 is actuated by the transistor 45, Ithecup 96 and coil 35 are attracted to the discs 75 and 76 and moveupwardly into close engagement with the disc 75 and begin to rotatetherewith. Thus the cup 96 and coil 35 constitute an electromagneticclutch that is engageable with the driven mechanism of the clock, thecoil 35 being an electromagnetic means that is actuable to engage theclutch. After this clutch has rotated through an are corresponding to apredetermined time of, say, fifteen minutes on the dial 81a, a contact49a on the clutch arm 96b encounters a stationary contact 49b, closingthe switch 49 of FIG. 1. As previously explained, this causes the coil35 to be deactuated, so that the clutch disengages and the spring 98restores the clutch to its initial position where the arm 96b is heldagainst Athe stop 99. Therefore whenever a disturbance puts the systeminto an alarm condition, that condition is maintained for at leastfifteen minutes by the operation of the clutch. The contact 49h arreststhe movement of the clutch, so that if for any reason the coil 35 failsto be deactuated when the switch.49 is closed, the clutch simply slipsrelative to the clock mechanism.

The disc 75 is thin and exible and slightly distorted so that it doesnot lie perfectly iiat against the disc 76. The disc 75 is alsoresilient, so that it presses Ithe clutch downwardly to assist itsdisengagement. Part of the disc 75 is always touching the 'cup 96 tofacilitate establishment of a good magnetic -flux path through the cup96 and discs 75 and 76 Whenthe coil 35 is again energized; thus only asmall amount of power is required to engage the clutch.

The electrical power requirements of the alarm system are not heavy,since the system is devoid of electromagnetic relays save for the relay28 in the alarm unit,

and this relay is not normally energized. Thus the single battery 14 canoperate the system in the event of a failure of the power source thatsupplied the line 31. The transistorized circuits of FIGS. 1 and 2 arehighly reliable, and the system is more stable and less costly thanconventional alarm systems that employ balanced relays. The mechanicallywound clock serves both to change the condition of the system from thenormal on guard condition to the normal off guard condition and to movethe clutch during an alarm condition, so that the clutch and clockmechanism serve as a timer and no separately driven timer'is required.

The oscillator 33 provides a signal of, say, 2500 cycles per second.Thus a burglar who does not have rather complex equipment cannotascertain what type of signal is being transmitted by the wires and 11to prevent an alarm. He can readily measure the six volts D.C. acrossthe Wires 10 and 11 but if he connects a six volt battery across thewires 10 andy 11, expecting that this will hold the bell inoperative, hewill short out the oscillatory signal and cause the bell to ring. Evenif he can measure the oscillatory signal he cannot easily replace itwithout special equipment and without knowledge of the alarm systemcircuitry. His task can be rendered still more difficult by using asignal device 33 and a receiver 18 capable of working at ultrasonicfrequencies which cannot be heard by tapping earphones across the wires10 and 11.

What we claim is:

1. An alarm system having a first normal condition, a second normalcondition, and an alarm condition, comprising a clock having aconstantly driven mechanism for changing the alarm system from onenormal condition to the -other at predetermined times, a clutch, meansresponsive to an alarm condition to engage the clutch with the drivenmechanism to move therewith from an initial position, and means operablewhen the clutch reaches a second position to terminate the alarmcondition and disenlgage the clutch from the driven mechanism.

2. An alarm system as claimed in claim 1, including restoring means forreturning the disengaged clutch to its initial position.

3. An alarm system as claimed in claim 1, wherein said means operablewhen the clutch reaches the second position comprise switch meansoperable by the clutch.

4. An alarm system as claimed in claim 3, wherein the clutch is anelectromagnetic clutch that is deenergized by operation of the switchmeans by the clutch on reaching the second position.

5. An alarm system as claimed in claim 1, wherein the clutch is anelectromagnetic clutch.

6. An alarm system as claimed in claim 5, including a thin, flexible,resilient and distorted disc of magnetizable material for pressing theclutch and driven mechanism apart.

7. An `alarm system as claimed in claim 6, wherein the driven mechanismis mechanically wound.

8. An alarm system as claimed in claim 1, wherein the first normalcondition is day time operation and the second normal condition is nighttime operation, and including switch means .actuable by the drivenmechanism at a predetermined position each day to change the alarmsystem from the' rst to the second normal condition.

9. An alarm system as claimed in claim 8, wherein the clock has a daywheel engaged by the driven mechanism at another predetermined positioneach day to move the day wheel one-seventh of a revolution, the daywheel having day pins positionable to actuate the switch means, as theday wheel is moved, to change the alarm system from the second to thefirst normal condition.

10. An alarm system as claimed in claim 9, wherein the day pins `arealso positionable to fail to actuate the switch means thus leaving thealarm system in the second normal condition.

11. An alarm system as claimed in claim 10, wherein the driven mechanismmoves the day wheel by engaging the day' pins.

12. An alarm system having at least a first normal condition, a secondnormal condition, and an alarm condition, comprising a clock having amovable mechanism for changing the .alarm system from any one normalcondition to another normal condition at predetermined times, meansresponsive to a disturbance of the system to change the system from anormal condition to an alarm condition, and means for maintaining thealarm condition until the clock mechanism has moved a predeterminedamount after the disturbance, thus maintaining the alarm condition forat least a predetermined time, the last mentioned means comprising aclutch actuable t-o engage the clock mechanism andmove therewith. l

13. An alarm system as claimed in claim 12, includ ing means fordeactuating the clutch after said predetermined amount of movement.

14. An alarm system having a normal on guard condition, a normal offguard condition, and an alarm condition, comprising a clock having aconstantly driven mechanism for changing the system alternately from onenormal condition to the other, electrical means responsive to adisturbance of the system to change the system from at least the onguard condition to an alarm condition, and means for maintaining thealarm condition for at least a predetermined time and comprising aclutch having a normal condiition in which it is disengaged from theclock mechanism, electromagnetic means for actuating the clutch toengage the clock mechanism and move therewith from an initial position,and restoring means operable when the clutch reaches a second positionto restore the clutch to its normal condition.

15. An alarm system as claimed in claim 14 having a rectifier powersupply, an alarm having a battery charged from the power supply, thebattery of the alarm being the sole battery in the system, the drivenmechanism of the clock being mechanically wound.

16. An alarm system as claimed in claim 14, wherein the electrical meanscomprise a signal device for normally supplying a signal to an alarm -torender the alarm inoperative, and means for rendering the signal deviceinoperative in response to the disturbance, the means for maintainingthe alarm condition comprising means for actuating said electromagneticmeans and means for maintaining the signal device inoperative while theclutch moves from its initial to its second position, the last mentionedactuating means being normally held inoperative by the signal.

17. An alarm system as claimed in claim 16, wherein thev means forrendering the signal device inoperative comprise means for shunting apower supply of the signal device during the disturbance, the actuatingmeans being responsive to resumption of power at the end of thedisturbance.

18. An alarm system as claimed in claim 14, wherein the electrical meanscomprise a signal device for normally supplying a signal to an alarm torender the alarm inoperative, and means for interrupting said signal inresponse to the disturbance.

19. An alarm system as claimed in claim 18, wherein the restoring meanscomprise means for restoring said signal after the clock mechanism hasmoved the clutch from the initial to the second position.

20. An alarm system as claimed in claim 18, wherein the electrical meansfurther comprise an electronic valve rendered operative -after thedisturbance to actuate the electromagnetic means. v

21. An alarm system as claimed in claim 20,'including means responsiveto the signal for normally rendering the electronic valve inoperative.

22. An alarm system as claimed in claim 18, wherein a line connects thesignal device to the alarm, a power supply for the signal device isconnected to the line, and the alarm normally provides a load on theline for the power supply wherebyan open circuit disturb-ance of theline changes the operation of the power supply, the signal interruptingmeans comprising means responsive to such change to render the signaldevice inoperative.

tion 'before theA signal device is again rendered operative.v

24. An alarm system as claimed in claim 23, wherein the signalinterrupting means comprise means for shunting the signal device andvalve.

25. An alarm system as claimed in claim 19, wherein the signal devicecomprisesan oscillator rendered inoperative in response to thedisturbance and maintained inoperative until the lclutch reaches itssecond position.A

References Cited bythe Examiner UNITED STATES PATENTS 2,177,102 10/1939Glover 340-323 X 2,436,824 3/1948 Potter 340--164 X 2,493,576 1/1950Foss 340-276 2,963,628 12/1960 Ostland 20G- 38.1 X 3,136,985 6/1964Robinson 20G-38 X 3,152,232 10/1964 Pardee 340--3091 NEILv c. READ,Primary Examiner. R. M. GOLDMAN, Assistant Examiner.

14. AN ALARM SYSTEM HAVING A NORMAL ON GUARD CONDITION, A NORMAL OFFGUARD CONDITION, AND AN ALARM CONDITION, COMPRISING A CLOCK HAVING ACONSTANTLY DRIVEN MECHANISM FOR CHANGING THE SYSTEM ALTERNATELY FROM ONENORMAL CONDITION TO THE OTHER, ELECTRICAL MEANS RESPONSIVE TO ADISTURBANCE OF THE SYSTEM TO CHANGE THE SYSTEM FROM AT LEAST THE ONGUARD CONDITION TO AN ALARM CONDITION, AND MEANS FOR MAINTAINING THEALARM CONDITION FOR AT LEAST A PREDETERMINED TIME AND COMPRISING ACLUTCH HAVING A NORMAL CONDITION IN WHICH IT IS DISEN-